Osteoarthritis (OA) is a chronic joint disease characterized by degeneration and destruction of articular cartilage as well as bone hyperplasia. The morbidity of OA is 50% in populations over 60 and 80% in those over 75, and the disability rate of OA is up to 53% (“Osteoarthritis Treatment Guidelines (Rev)”, Chinese Medical Association of Orthopaedics, 2007). OA is common in joints suffering from heavy burden and frequent activities, such as knee, namely knee osteoarthritis (KOA). Knee osteoarthritis is one of major diseases which lead to activity dysfunction in elder people, and leads to heavy financial burden to health insurance and family.
At present, the general principle for treating knee osteoarthritis (KOA) is the combination of drug and non-drug therapy with surgeries when necessary so as to achieve the relief or elimination of pain, deformity correction, joint function improvement or restoration, thereby improving quality of life.
Drug therapy mainly comprises analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs), intra-articular injection of hyaluronic acid (HA) or corticosteroids, drugs for improving the state of illness and cartilage protection agents, etc. These drugs can to some extent delay the course of the disease and improve patients symptoms. However, the efficacy is limited, the pathological progression is irreversible, the cartilage damage is irreparable, and most of the drugs have obvious side effects.
When conventional therapy turns out to be invalid, surgeries are needed for the patients with joint deformity and joint dysfunction. Surgical treatments are conducted mainly by arthroscopic (endoscope) and open surgery. Even though they can temporarily relieve pain, they are expensive and have poor long-term effect. It is reported those 10-15 years after joint replacement surgery, the prosthesis started to get worn or even loosen. Therefore, the present studies aim at exploring novel treatments and repair strategies.
Tissue engineering dedicates in autologous chondrocyte transplantation or matrix-induced autologous chondrocyte transplantation and provides the possibility of long-term solution for biologically repairing or regenerating the degraded joint tissues. However, this type of technology is mainly limited in treating large cartilage defects. Factors such as the damages to the donors' site, the dedifferentiation and the limited survival time of cartilage cells make the method being unsuitable for KOA patients.
Currently, many studies are targeting to allogeneic mesenchymal progenitor cells from other sources, such as adipose allogeneic mesenchymal progenitor cells. Adipose allogeneic mesenchymal progenitor cells are characterized by their extensive sources, safety, low immunogenicity and excellent immunoregulation ability, thereby exhibiting a unique effect on the treatments of KOA. The applicant has also developed autologous adipose mesenchymal progenitor cells with definite clinical curative effects. However, autologous adipose can not be provided by some KOA patients, such as patients having infectious diseases, or the old and emaciated ones, resulting in those patients unable to use autologous fat mesenchymal progenitor cells to treat KOA.
Therefore, the applicant develops allogeneic mesenchymal progenitor cells to meet the demands of those patients.